#ifndef _RRPRIMITIVEASSEMBLER_HPP
#define _RRPRIMITIVEASSEMBLER_HPP
/*-------------------------------------------------------------------------
 * drawElements Quality Program Reference Renderer
 * -----------------------------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *//*!
 * \file
 * \brief Primitive assembler
 *//*--------------------------------------------------------------------*/

#include "rrDefs.hpp"
#include "rrVertexPacket.hpp"

namespace rr
{
namespace pa
{

struct Triangle
{
	enum
	{
		NUM_VERTICES = 3
	};

	Triangle (void)
		: v0				(DE_NULL)
		, v1				(DE_NULL)
		, v2				(DE_NULL)
		, provokingIndex	(-1)
	{
	}

	Triangle (VertexPacket* v0_, VertexPacket* v1_, VertexPacket* v2_, int provokingIndex_)
		: v0				(v0_)
		, v1				(v1_)
		, v2				(v2_)
		, provokingIndex	(provokingIndex_)
	{
	}

	VertexPacket* getProvokingVertex (void)
	{
		switch (provokingIndex)
		{
			case 0: return v0;
			case 1: return v1;
			case 2: return v2;
			default:
				DE_ASSERT(false);
				return DE_NULL;
		}
	}

	VertexPacket*	v0;
	VertexPacket*	v1;
	VertexPacket*	v2;

	int				provokingIndex;
};

struct Triangles
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		const int provokingOffset = (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (2);

		for (size_t ndx = 0; ndx + 2 < numVertices; ndx += 3)
			*(outputIterator++) = Triangle(vertices[ndx], vertices[ndx+1], vertices[ndx+2], provokingOffset);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return vertices / 3;
	}
};

struct TriangleStrip
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		if (numVertices < 3)
		{
		}
		else
		{
			VertexPacket* vert0 = vertices[0];
			VertexPacket* vert1 = vertices[1];
			size_t ndx = 2;

			for (;;)
			{
				{
					if (ndx >= numVertices)
						break;

					*(outputIterator++) = Triangle(vert0, vert1, vertices[ndx], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (2));
					vert0 = vertices[ndx];

					ndx++;
				}

				{
					if (ndx >= numVertices)
						break;

					*(outputIterator++) = Triangle(vert0, vert1, vertices[ndx], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (1) : (2));
					vert1 = vertices[ndx];

					ndx++;
				}
			}
		}
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 3) ? (0) : (vertices - 2);
	}
};

struct TriangleFan
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		if (numVertices == 0)
		{
		}
		else
		{
			const int			provokingOffset	= (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (1) : (2);
			VertexPacket* const	first			= vertices[0];

			for (size_t ndx = 1; ndx + 1 < numVertices; ++ndx)
				*(outputIterator++) = Triangle(first, vertices[ndx], vertices[ndx+1], provokingOffset);
		}
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 3) ? (0) : (vertices - 2);
	}
};

struct Line
{
	enum
	{
		NUM_VERTICES = 2
	};

	Line (void)
		: v0				(DE_NULL)
		, v1				(DE_NULL)
		, provokingIndex	(-1)
	{
	}

	Line (VertexPacket* v0_, VertexPacket* v1_, int provokingIndex_)
		: v0				(v0_)
		, v1				(v1_)
		, provokingIndex	(provokingIndex_)
	{
	}

	VertexPacket* getProvokingVertex (void)
	{
		switch (provokingIndex)
		{
			case 0: return v0;
			case 1: return v1;
			default:
				DE_ASSERT(false);
				return DE_NULL;
		}
	}

	VertexPacket*	v0;
	VertexPacket*	v1;

	int				provokingIndex;
};

struct Lines
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		const int provokingOffset = (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (1);

		for (size_t ndx = 0; ndx + 1 < numVertices; ndx += 2)
			*(outputIterator++) = Line(vertices[ndx], vertices[ndx+1], provokingOffset);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return vertices / 2;
	}
};

struct LineStrip
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		if (numVertices == 0)
		{
		}
		else
		{
			VertexPacket* prev = vertices[0];

			for (size_t ndx = 1; ndx < numVertices; ++ndx)
			{
				*(outputIterator++) = Line(prev, vertices[ndx], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (1));
				prev = vertices[ndx];
			}
		}
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 2) ? (0) : (vertices - 1);
	}
};

struct LineLoop
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		if (numVertices < 2)
		{
		}
		else
		{
			VertexPacket* prev = vertices[0];

			for (size_t ndx = 1; ndx < numVertices; ++ndx)
			{
				*(outputIterator++) = Line(prev, vertices[ndx], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (1));
				prev = vertices[ndx];
			}

			*(outputIterator++) = Line(prev, vertices[0], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (1));
		}
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 2) ? (0) : (vertices);
	}
};

struct Point
{
	enum
	{
		NUM_VERTICES = 1
	};

	Point (void)
		: v0(DE_NULL)
	{
	}

	Point (VertexPacket* v0_)
		: v0(v0_)
	{
	}

	VertexPacket* v0;
};

struct Points
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		DE_UNREF(provokingConvention);

		for (size_t ndx = 0; ndx < numVertices; ++ndx)
			*(outputIterator++) = Point(vertices[ndx]);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices);
	}
};

struct LineAdjacency
{
	enum
	{
		NUM_VERTICES = 4
	};

	LineAdjacency (void)
		: v0				(DE_NULL)
		, v1				(DE_NULL)
		, v2				(DE_NULL)
		, v3				(DE_NULL)
		, provokingIndex	(-1)
	{
	}

	LineAdjacency (VertexPacket* v0_, VertexPacket* v1_, VertexPacket* v2_, VertexPacket* v3_, int provokingIndex_)
		: v0				(v0_)
		, v1				(v1_)
		, v2				(v2_)
		, v3				(v3_)
		, provokingIndex	(provokingIndex_)
	{
	}

	VertexPacket* getProvokingVertex (void)
	{
		switch (provokingIndex)
		{
			case 1: return v1;
			case 2: return v2;
			default:
				DE_ASSERT(false);
				return DE_NULL;
		}
	}

	VertexPacket*	v0;
	VertexPacket*	v1;
	VertexPacket*	v2;
	VertexPacket*	v3;

	int				provokingIndex;
};

struct LinesAdjacency
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		const int provokingOffset = (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (1) : (2);

		for (size_t ndx = 0; ndx + 3 < numVertices; ndx += 4)
			*(outputIterator++) = LineAdjacency(vertices[ndx], vertices[ndx+1], vertices[ndx+2], vertices[ndx+3], provokingOffset);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return vertices / 4;
	}
};

struct LineStripAdjacency
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		const int provokingOffset = (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (1) : (2);

		for (size_t ndx = 0; ndx + 3 < numVertices; ++ndx)
			*(outputIterator++) = LineAdjacency(vertices[ndx], vertices[ndx+1], vertices[ndx+2], vertices[ndx+3], provokingOffset);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 4) ? (0) : (vertices - 3);
	}
};

struct TriangleAdjacency
{
	enum
	{
		NUM_VERTICES = 6
	};

	TriangleAdjacency (void)
		: v0				(DE_NULL)
		, v1				(DE_NULL)
		, v2				(DE_NULL)
		, v3				(DE_NULL)
		, v4				(DE_NULL)
		, v5				(DE_NULL)
		, provokingIndex	(-1)
	{
	}

	TriangleAdjacency (VertexPacket* v0_, VertexPacket* v1_, VertexPacket* v2_, VertexPacket* v3_, VertexPacket* v4_, VertexPacket* v5_, int provokingIndex_)
		: v0				(v0_)
		, v1				(v1_)
		, v2				(v2_)
		, v3				(v3_)
		, v4				(v4_)
		, v5				(v5_)
		, provokingIndex	(provokingIndex_)
	{
	}

	VertexPacket* getProvokingVertex (void)
	{
		switch (provokingIndex)
		{
			case 0: return v0;
			case 2: return v2;
			case 4: return v4;
			default:
				DE_ASSERT(false);
				return DE_NULL;
		}
	}

	VertexPacket*	v0;
	VertexPacket*	v1;	//!< adjacent
	VertexPacket*	v2;
	VertexPacket*	v3;	//!< adjacent
	VertexPacket*	v4;
	VertexPacket*	v5;	//!< adjacent

	int				provokingIndex;
};

struct TrianglesAdjacency
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		const int provokingOffset = (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (4);

		for (size_t ndx = 0; ndx + 5 < numVertices; ndx += 6)
			*(outputIterator++) = TriangleAdjacency(vertices[ndx], vertices[ndx+1], vertices[ndx+2], vertices[ndx+3], vertices[ndx+4], vertices[ndx+5], provokingOffset);
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return vertices / 6;
	}
};

struct TriangleStripAdjacency
{
	template <typename Iterator>
	static void exec (Iterator outputIterator, VertexPacket* const* vertices, size_t numVertices, rr::ProvokingVertex provokingConvention)
	{
		if (numVertices < 6)
		{
		}
		else if (numVertices < 8)
		{
			*(outputIterator++) = TriangleAdjacency(vertices[0], vertices[1], vertices[2], vertices[5], vertices[4], vertices[3], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (4));
		}
		else
		{
			const size_t primitiveCount = getPrimitiveCount(numVertices);
			size_t i;

			// first
			*(outputIterator++) = TriangleAdjacency(vertices[0], vertices[1], vertices[2], vertices[6], vertices[4], vertices[3], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (4));

			// middle
			for (i = 1; i + 1 < primitiveCount; ++i)
			{
				// odd
				if (i % 2 == 1)
				{
					*(outputIterator++) = TriangleAdjacency(vertices[2*i+2], vertices[2*i-2], vertices[2*i+0], vertices[2*i+3], vertices[2*i+4], vertices[2*i+6], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (2) : (4));
				}
				// even
				else
				{
					*(outputIterator++) = TriangleAdjacency(vertices[2*i+0], vertices[2*i-2], vertices[2*i+2], vertices[2*i+6], vertices[2*i+4], vertices[2*i+3], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (4));
				}
			}

			// last

			// odd
			if (i % 2 == 1)
				*(outputIterator++) = TriangleAdjacency(vertices[2*i+2], vertices[2*i-2], vertices[2*i+0], vertices[2*i+3], vertices[2*i+4], vertices[2*i+5], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (2) : (4));
			// even
			else
				*(outputIterator++) = TriangleAdjacency(vertices[2*i+0], vertices[2*i-2], vertices[2*i+2], vertices[2*i+5], vertices[2*i+4], vertices[2*i+3], (provokingConvention == rr::PROVOKINGVERTEX_FIRST) ? (0) : (4));
		}
	}

	static size_t getPrimitiveCount (size_t vertices)
	{
		return (vertices < 6) ? 0 : ((vertices - 4) / 2);
	}
};

} // pa
} // rr

#endif // _RRPRIMITIVEASSEMBLER_HPP
